Preheat the oven to 175°C/347°F.

Cut the cauliflower into florets, place into a bowl with salted water and set aside for five minutes.

Rinse and drain, then steam for 10 minutes.

In medium soup pot add the celery stalks, parsnip, parsley and onion, cover with the purified water and bring to boil over medium heat.

Turn the heat to low, and simmer for 10 minutes. (if you don't have a steamer for the cauliflower, you can add the florets into a large colander or a bamboo steaming basket and place this over the boiling water).

While the soup is boiling, prepare the chickpeas:

Rinse the canned chickpeas, drain and add onto a baking tray.

Drizzle with oil, add mustard and cayenne, and toss to coat evenly.

Roast for 15 minutes, until golden. Remove from the oven and set aside.

Transfer the liquid, vegetables and steamed cauliflower into the blender, add tahini, garlic, salt, pepper, cumin, caraway and lemon juice, and pulse to obtain a creamy soup.

Pour into serving bowls, garnish with roasted chickpeas and serve warm.